1. Field of the Invention
The invention pertains to the art of manufacturing processes. It finds application in the manufacture of electrodes for lamps and in particular in the manufacture of electrodes for ceramic metal halide lamps.
2. Discussion of the Art
A current method of manufacturing electrodes for ceramic metal-halide lamps uses fixtures with precision v-slots and spring clamps to align component wire axes. These fixtures are difficult to manufacture with a level of precision needed to meet product requirements. Furthermore, each product type requires a custom-built fixture to handle different wire diameters. Additionally, each component of the electrode must be pre-cut to length, singulated, and fed into the fixture from the side, contributing to the complexity of a feeding system.
Another problem with the existing process is the manufacture and handling of electrode components, namely electrode tips. It is believed that these tips are manufactured by hand. The tips are expensive. Furthermore, new low-wattage products will require even smaller electrodes. Current manufacturing techniques appear unable to accommodate the requisite smaller size.
Once the tips are manufactured, they must be separated and delivered to an assembly fixture. The current handling process involves bowl feeding electrode tips, molybdenum overwinds and niobium wire shanks into vibratory tracks. The tracks deliver the electrode components or parts to an escapement where they are removed by a vacuum pick-and-place device. The pick-and-place device orients and delivers the parts into assembly fixtures where they are welded together. This technique works reasonably well for tips with shank diameters larger than 0.010xe2x80x3; however, it is increasingly more difficult to separate, pickup, and orient the tips in an assembly fixture as the tips get smaller.
To date, available lamp electrode manufacturing techniques are unable to accommodate the reduced size of electrodes needed for low wattage lamps. Additionally, available manufacturing techniques are too expensive to be useful in a high-volume manufacturing environment necessary to make manufacture and sale of low wattage lamps practical. Thus, the need exists to provide a method for manufacturing electrodes for lamps that is fast, inexpensive, and amenable to high production volumes.
An exemplary method for making a lamp electrode is suitable for automation and adaptable for use on a machine tool. The method comprises the steps of cutting a first material having a first end, to a desired length, thereby defining a second end, welding a first end of a second material to the second end of the first material, cutting the second material to define a second end of the second material, welding a first end of a third material to the second end of the second material, cutting the third material to define a second end of the third material, and securing a coil to the second end of the third material.
One advantage of the present invention is that it can be implemented on a machine tool.
Another advantage of the present invention is that it allows for the manufacture of electrode components with very low unit-to-unit dimensional variation.
A further advantage of the present invention is that it provides for precise electrode component alignment while eliminating the need for custom fixtures.
Still another advantage of the present invention is that it provides for the rapid and inexpensive manufacture of electrodes.
Another advantage of the present invention is that it provides for the manufacture of extremely small electrodes.